1. Field of the Invention
This invention relates to an electronic clinical thermometer, particularly an electronic clinical thermometer of the type having a hermetically sealed envelope the interior of which accommodates an alarm tone generating unit.
2. Description of the Prior Art
Various improvements made possible by advances in electronic techniques have been proposed for electronic clinical thermometers in recent years. Among them is an alarm which, when activated, informs one that a temperature measurement has ended or that a measurement error has occurred. However, an integrated electronic clinical thermometer incorporating both a temperature sensing unit and the alarm in one body has not yet been put into practical use.
While no particular difficulty is involved in providing the conventional electronic clinical thermometer with an acoustic generator, a problem of maintaining liquid-tightness is encountered. Specifically, unless the thermometer envelope is equipped with holes through which sound may pass, an alarm tone of satisfactory volume cannot be obtained, particularly with a small-size clinical thermometer when inserted into an armpit to sense body temperature. The holes make it impossible to achieve a liquid-tight structure. Another drawback involves cleaning and prevention of infection, for it is known that a surface having holes or recesses does not readily lend itself to the thorough washing and sterilization that electronic clinical thermometers require. For these reasons, a practical electronic clinical thermometer having a built-in alarm has not been realized.